Don't waste time trying to CSE labels, phis, inline asm. Definitely avoid cse implicit-def for obvious performance reason.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98009 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index ce8ebbc601..a0023feb98 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -171,6 +171,10 @@ bool MachineCSE::hasLivePhysRegDefUse(MachineInstr *MI, MachineBasicBlock *MBB){
 }
 
 bool MachineCSE::isCSECandidate(MachineInstr *MI) {
+  if (MI->isLabel() || MI->isPHI() || MI->isImplicitDef() ||
+      MI->isKill() || MI->isInlineAsm())
+    return false;
+
   // Ignore copies or instructions that read / write physical registers
   // (except for dead defs of physical registers).
   unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;